During the next year we plan to continue our studies on the structure and function of complex oligosaccharides on mammalian cell membranes. Glycopeptides will be prepared and the sugar composition determined by gas liquid chromatography. The sequence of the sugars in the oligosaccharides will be determined by the sequential glycosidase digestion combined with methylation analysis. Such studies will be performed on normal cells and mutant cells with altered surface sugars. In addition, attempts will be made to isolate more mutant cell lines with different alterations in membrane sugar structure. BIBLIOGRAPHIC REFERENCES: Kornfeld, R., and Ferris, C. 1975. Interaction of Immunoglobulin Glycopeptides with Concanavalin A. J. Bill. Chem. 250:2614-2619. Gottlieb, C., Baenziger, J., and Kornfeld, S. 1975. Deficient Uridine Diphosphate-N-acetylglucosamine: Glycoprotein N-Acetylglucosaminyltransferase Activity in a Clone of Chinese Hamster Ovary Cells with Altered Sugar Glycoproteins. J. Biol. Chem. 250:3303-3309.